Denver Police are looking for two suspects. One is a black male, 6 feet tall, 180 lbs., wearing gray hoodie, black pants and a Carolina baseball cap. The other suspect is a black male wearing a black and white checkered shirt.

The pot celebration Saturday was the first since Colorado and Washington made marijuana legal for recreational use.

A sizable police force on motorcycles and horses watched the celebration. But officers didn't arrest people for smoking in public, which is still illegal. A crowd estimate wasn't immediately available, but organizers predicted some 80,000 at the nation's largest 4/20 observation.